Mechanics

HESITATION / FUEL PRESSURE / STALLI

1995 Mercedes Benz S500

Engine Performance problem
1995 Mercedes Benz S500 V8 Wheel Drive Type unknown Automatic 90,500 miles

I have been having trouble with my car hesitating when I accelerate - even on the highway when I am putting continual pressure on the accelerator, as well as city streets. The check engine light was on, however, after a mechanic reset something (?) The light went off. It is now back on. On occasion, the car will stall when at a stop light (it seems like it only stalls after the car has been driven for 10 or 15 miles - or more). While at a stop, if you keep giving the car gas - while in neutral - it won't die. I have had it to the car dealer on two occasions as well as to a reputable mercedes mechanic. The fuel pump has been cleaned and then replaced, the fuel tank emptied and cleaned, the screen from fuel tank to pump cleaned. After the mechanic took it to the dealer to put it on their computer it showed that the wiring harness needed to be replaced. It was replaced as well, but it is still having the same problems. It has been suggested that there may be a problem with air in the tank, not enough pressure allowing a steady flow of gas, a faulty fuel injection system, and just about anything else having to do with the fuel system. It has also been suggested that the fuel cap be replaced or to have the ignition checked. The iginition was supposed to have been checked by the dealer about 6 months ago with no problem identified. I had the car to the dealer because my key would stick in the ignition for a few seconds (and eventually having to wait about 10 seconds) after the car was turned off. The car is used mainly for short trips (20-30 miles a day) with an occasional long trip to WI (about 900 miles). The mechanic indicated that he has done all he knows to do. We have spent over $2500 checking out this hesitation problem and the problem is not resolved. I don't doubt that the parts that have been replaced were needed - but I don't know what else to do or where to take the car. I have not been satisfied with the local dealer and the mechanic is now at a loss as to what to do. The next closest dealer is 100 miles away - and although I don't have a problem taking it there, I cannot be without a car for long. In additon to suggestions on the possible causes for the problems, is it necessary to take the car to a mercedes dealer or mercedes specialist to have these problems checked and/or repaired? Also. If the car is having these problems, is it wise to keep putting money into the car to repair things or should I look into trading it in? Please help! I would be grateful for any suggestions for resolving this problem. Thanks.
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Sharon Stratton
March 18, 2008.




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Tiny
Sharon Stratton
Mar 18, 2008.
I have a '95 S500 with 101k and have the EXACT same problems that you stated and have been trying to get the issues " resolved" for a year now to no avail. Have had replaced: both oxygen sensors, new transmission, full tune-up, air mass meter, oil sending unit, fuel pump, fuel filter, air box, fuel injection cleaning, replaced gas cap, breather valve and more! It's still doing it when it warms up.

2 independent mechanics have now worked on it, the dealer says that it is not throwing a code and they can't replicate the " issue" - but they did replace the brakes (that have been on for less than 10,000 miles.), Replace the spark plugs (at $50 each!) And tell me that I have a fault in the seatbelts and recomended replacement of both passenger side seatbelts and a micro-switch in both seat buckles?

I've kept the car up to date on all services and it still looks amazing- the highest price I could get for it on trade was $4,000! $1,000 less than the transmission alone cost. Or 1/10th of what I paid for it 7 years ago- therefore, I'm resigned to keeping it but would really like to get this fixed so that I can occasionally drive it.

At this point the mechanic is saying it's the new transmission, the transmission shop is saying it's not their transmission (it's been back there 6 times for problems in less than 1,500 miles) the mechanics are now just guessing and replacing things and the bills keep adding up! The latest suggestion was replace the crank position sensor, but at over $1,000 I'd like something more solid than " we'll try this, but it may not be the problem"!

If you find a " fix", please let me know!

Tiny
Rottisnot
May 22, 2008.
Try replacing your ignition coils and wires. I have a 95 C36 that had the same issues - went away after I replaced the O2 sensors, MAF, plugs, coil packs and wires.

Tiny
Drewsome2
May 22, 2008.
You had the same problem I did. After spending $7000 on repairs, found out all it was was there was water in my gas tank! Only took a $1.49 bottle of dry gas poured in my gas tank to rid it of the water that built up in there due to condensation! After 2 years of hell, thats all it was! Currently in lawsuit with Mercedes dealership who diagnosed it with everything but what was wrong with it!

Tiny
Tominfl
Sep 28, 2008.

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